The elastic compliance of cementitious materials increases slightly, and their time-dependent “creep” compliance increases significantly with increasing temperature. The present contribution provides quantitative insight into this topic. Thereby, the focus rests on mature cement paste made from Ordinary Portland cement and distilled water. Macroscopic creep experiments were performed, in order to quantify both elastic and creep moduli in the range of temperatures from 20 ℃ to 45 ℃. The experimental results regarding temperature-dependent values of the modulus of elasticity are validated herein using original results from ultrasonics testing. Finally, a multiscale model was used to establish a link to well-known stiffness constants of unhydrated cement clinker, as well as to temperature-dependent elastic and creep stiffness properties of nanoscopic hydrate-gel needles.